Over the past two decades, gender-sensitive services have emerged in response to the multidimensional profile of problems that women display upon admission to substance abuse treatment. This has been accompanied by considerable research on women in both mixed-gender treatment settings and specialized women-only settings, and some evidence has accumulated to suggest that women admitted to women-only programs have better retention and better outcomes relative to traditional mixed-gender programs. However, most women in the United States are treated in nonspecialized mixed-gender settings and little empirical research has measured the degree to which gender-sensitive programming occurs in such settings, related it to treatment outcomes, or assessed whether the value added offsets the costs. The present study will: 1) Assess naturally occurring variation in gender-sensitive programming for women across traditional, mixed- gender short-term residential treatment programs in Washington State;2) Determine value-added from gender-sensitive programming, in terms of proximal and distal client outcomes for women;3) Determine which components or practices of gender-sensitive programming in mixed-gender settings appear promising;and 4) Determine whether such programming is cost effective and cost beneficial. The target population is women 18 years old and over admitted to one of 15 short-term residential mixed-gender programs in Washington from April 1, 2005 through March 31, 2009. The principal independent variable is program-level gender-sensitivity, which will be established through interviews with multiple key informants at each program site using semistructured protocols. Distal outcomes (repeat treatment episodes, employment rates and earned income, dependence on unearned income supports, and involvement with the criminal justice and child welfare systems) will be tracked for 2 years pre- and 2 years postadmission from administrative data sources.